The heart is enclosed in a double layered membrane termed the pericardium. The pericardium and its serous fluid protect the heart and lubricate the moving surfaces of the heart. The pericardium is composed of two layers: the outermost fibrous pericardium and the inner serous pericardium. The serous pericardium is divided into two layers, the parietal pericardium, which is fused to the fibrous pericardium, and the visceral pericardium (also termed epicardium). Pericardial serous fluid is found in the pericardial cavity (also termed the pericardial space) between the parietal pericardium and visceral layer.
Accessing of the pericardium may facilitate, for example, drug delivery, a pericardiocentesis procedure (aspiration of pericardial fluid typically for diagnosis of a pericardial disease), left atrial appendage removal, coronary artery bypass grafting, or placement of a reflection-facilitation element as described in US Patent Application Publication 2013/0103028 to Tsoref et al., which issued as U.S. Pat. No. 9,242,122 and which is incorporated herein by reference.
Complications may arise during surgical procedures to access the pericardium, and injury may be caused to internal organs such as the liver, stomach and lungs. Therefore, safe and efficient means of accessing the pericardium are desirable.